You can store and retrieve anything you like in this hash. It's contents will automatically be stored in Gimp, and can be accessed in later invocations of your plug-in. Be aware that other plug-ins store data in the same "hash", so better prefix your key with something unique, like your plug-in's name. As an example, the Gimp::Fu module uses "function_name/_fu_data" to store its data.

This module might use a persistant implementation, i.e. your data might survive a restart of the Gimp application, but you cannot count on this.

Gimp::Data will try to freeze your data when you pass in a reference. On retrieval, the data is thawed again. See Storable for more info. This might be implemented through either Storable or Data::Dumper, or not implemented at all (i.e. silently fail) ;)